Problem: Simplify the expression. $(5y+7)(y-7)$
Explanation: First distribute the ${5y+7}$ onto the ${y}$ and ${-7}$ $ = {y}({5y+7}) + {-7}({5y+7})$ Then distribute the ${y}.$ $ = ({y} \times {5y}) + ({y} \times {7}) + {-7}({5y+7})$ $ = 5y^{2} + 7y + {-7}({5y+7})$ Then distribute the ${-7}$ $ = 5y^{2} + 7y + ({-7} \times {5y}) + ({-7} \times {7})$ $ = 5y^{2} + 7y - 35y - 49$ Finally, combine the $x$ terms. $ = 5y^{2} - 28y - 49$